This invention relates to a fruit harvester of the type which includes a mobile frame adapted to travel over the ground, and a rotatable shaker member supported on this mobile frame adapted during travel of the frame to engage the growth supporting the fruit and to shake this growth whereby the fruit falls free. A common form of such harvester is a so-called berry harvester, which includes a pair of opposed rotatable shaker members positioned to engage opposite sides of a row of berry plants as the harvester moves along the rows.
In a common form of harvester, and as exemplified by the harvester disclosed in Christie et al., U.S. Pat. No. 3,344,591, so-called free-wheeling shaker members are provided disposed opposite each other which are rotated by engagement with the plants being processed and as the harvester travels along the row, so that the peripheral speed of the shakers is essentially the travel speed of the harvester along the ground. Superimposed on this free-wheeling rotary movement is an oscillatory movement in each of the shakers, whereby such rotates back and forth over a short arc, with the imparting of a shaking movement to the plants processed. In Christie et at., this shaking movement, also described as an oscillatory vibration, might be at a frequency of a thousand cycles per minute, and with the amplitude of vibration being in the range of an inch or less.
Generally speaking, in harvesters having rotatable, free-wheeling shakers with vibratory movement superimposed upon the movement of the shakers, vibration frequency tends to be relatively high, there is a limited amount of control in the back and forth movement in which a shaker partakes, and shaking characteristics tend to be adversely affected by traveling through heavy material.
A general object of this invention is to provide an improved fruit harvester which includes a rotatable shaker which may be operated effectively with a lower oscillation rate in the shaker.
Another object is to provide an improved fruit harvester where the amplitude of oscillation in a rotatable shaker may be selected to be considerably larger than typical oscillation amplitudes known in the past.
A further object is to provide a harvester which affords greater control by the operator of the back and forth oscillatory movement in a shaker.
Another object is to provide a harvester with a rotatably mountable oscillating shaker, where the shaker is not free-wheeling but may be rotated under power to have a net circumferential motion which equals that of the speed of the harvester over the ground.
A further object is to provide a harvester which includes an oscillatable member which is powered back and forth by motor, and power-transmitting means connecting this oscillatable member with a rotatable shaker which includes slippage means allowing controlled relative slippage between movement of the oscillatable member and movement of the shaker.
Yet another object is to provide such a harvester where the slippage is adjustable. More particularly, the slippage is adjustable with the oscillatable member rotated in one direction and also adjustable with the oscillatable member rotated in the opposite direction, and one of these adjustments may be made independently of the other.
A further object is to provide such a harvester where the slippage means comprises a rotary hydraulic pump, with valving interposed between inlet exhaust sides of the pump adjustable to control the extent to which casing movement follows rotor movement, with the rotor angularly shifted in either of opposite directions.